The severe storm threat is fading, especially away from the coast, due to a lack of instability

Hi everyone. Just jumping in with a quick afternoon update on the forecast for severe weather in the Houston area. The bottom line is that the window for severe thunderstorms away from the immediate coast is closing quickly this afternoon.

What has happened is that rainfall near the coast and inland this morning has sapped the atmosphere of some of the instability needed to drive severe weather. (Such instability is necessary to promote the kinds of rising air that fuel strong thunderstorms). As a result the atmospheric environment is not really capable of supporting the kinds of supercells that produce tornadoes and other severe activity. We could still see a few isolated tornadoes this afternoon, but the threat is fading.

In terms of precipitation, we’ve seen the heaviest rainfall so far along the coast today, near a warm front at the surface. A couple of inches have fallen and we’re likely to see additional accumulations over the next few hours with sporadic pulses of heavier rainfall. It is these coastal regions from Matagorda Bay to Galveston Bay and up toward Port Arthur that the greatest potential for strong thunderstorms lies. As this system continues to propagate to the east, the threat of heavy rainfall and storm activity, even along the coast, will diminish late this afternoon and evening.